Lidded drum

ABSTRACT

A lidded drum of synthetic material includes a clamping ring of metal for fastening the lid on the upper drum rim, wherein the clamping ring is U-shaped in cross section and engages in the closed state with its upper leg over the lid rim and the lower leg engages under an annular contact surface of a border of the drum wall. The contact surface extends perpendicularly or obliquely relative to the longitudinal axis of the drum. The contact surface is arranged below the upper drum rim and constitutes the upper limitation of an indentation in the upper portion of the drum wall. The lid rim formed by an inner rim, an outer rim, and a connecting ring, has a U-shaped cross sectional profile which is open toward the bottom and includes a sealing bed for placing or foaming a lid seal therein, wherein the lid seal is pressed in the closed state of the drum lid by the clamping force of the clamping ring against the upper lid rim. An annular bead is integrally formed on the connecting leg of the upper and lower legs of the clamping ring, wherein the annular bead is directed radially inwardly and, when the clamping ring is closed, the annular bead rests in a positively engaging manner against the outer rim of the lid for securing the lid on the upper lid rim.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lidded drum of synthetic materialwith a clamping ring of metal for fastening the lid on the upper drumrim, wherein the clamping ring is U-shaped in cross section and engagesin the closed state with its upper leg over the lid rim and the lowerleg engages under an annular contact surface of a border of the drumwall which contact surface extends perpendicularly or obliquely relativeto the longitudinal axis of the drum. The contact surface is arrangedbelow the upper drum rim and constitutes the upper limitation of anindentation in the upper portion of the drum wall. The lid rim formed byan inner rim, an outer rim, and a connecting ring, has a U-shaped crosssectional profile which is open toward the bottom and includes a sealingbed for placing or foaming a lid seal therein, wherein the lid seal ispressed in the closed state of the drum lid by the clamping force of theclamping ring against the upper lid rim.

2. Description of the Related Art

In lidded drums of this type as known from U.S. Pat. No. 5,301,853, thesealing effect of the drum lid is effected by an axial pretensioning ofthe lid seal which is placed on the upper lid rim, wherein the axialpretensioning force is produced during the closing of the clamping ringover the two inclined legs of the clamping ring which slide over the lidrim and the drum border. In lidded drums which are permitted to be usedfor storing and transporting dangerous liquids, certain demands are madewith respect to the storage and transport safety which are tested bymeans of prescribed registration examinations, in which the lidded drumsare subjected to a lateral drop onto the wall, a diagonal drop onto thelid rim, a static internal pressure measurement, and a stacking load.

In the lidded drum according to U.S. Pat. No. 5,301,853, the necessarystrength of the ring is achieved by using a relatively great thicknessof the sheet metal of the clamping ring, wherein, when the drum drops,for example, from the loading surface of a truck, leaks are prevented inthe drum lid and, when the drum drops from a greater height, aseparation of the lid from the drum due to deformations of the clampingring are prevented. The disadvantages of this known lidded drum are theweight of the clamping ring because of the relatively large materialthickness of the ring and the high price of manufacturing the ring.

SUMMARY OF THE INVENTION

It is the primary object of the present invention to further develop thelidded drum described above with respect to the tightness of the drumlid when the drum drops from middle or large heights.

In accordance with the present invention, the above object is met byproviding an annular bead integrally formed on the connecting leg of theupper and lower legs of the clamping ring, wherein the annular bead isdirected radially inwardly and, when the clamping ring is closed, theannular bead rests in a positively engaging manner against the outer rimof the lid for securing the lid on the upper lid rim.

The lidded drum of synthetic material according to the present inventionwith a clamping ring of metal for fastening the drum lid on the upperdrum rim has compared to the known lidded drums the advantage of animproved strength with respect to drops and a clamping ring with reducedmaterial thickness leading to the reduction of the weight of theclamping ring and to a reduced manufacturing cost of the clamping ringbecause of a reduced use of material.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of the disclosure. For a better understanding of the invention, itsoperating advantages, specific objects attained by its use, referenceshould be had to the drawing and descriptive matter in which there areillustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is an elevational view of the lidded drum; and

FIGS. 2 and 3 are sectional views, on a larger scale, showing portionsof the upper area of the lidded drum with two different embodiments ofthe clamping ring closure of the drum lid.

DETAILED DESCRIPTION OF THE INVENTION

The lidded drum 1 manufactured of synthetic material as shown in FIG. 1is composed of a drum wall 2, a lower bottom 3, a drum lid 4, as well asa clamping ring of metal for fastening the lid 4 on the upper drum rim6.

In both embodiments of the drum illustrated in FIGS. 2 and 3, theclamping ring 5, which has a U-shaped cross sectional profile, engageswith its upper leg 7 over the lid rim 8 and engages with its lower leg 9on the annular contact surface 11 of a border or projection 12 at thedrum wall 2, wherein the annular contact surface 11 extends obliquelyrelative to the longitudinal axis 10 of the drum, and wherein the border12 is arranged underneath the upper drum rim 6 and forms the upperlimitation of an indentation 13 in the upper portion of the drum wall 2.The drum rim 8 formed by an inner rim 14, an outer rim 15, and aconnecting ring 16 has a downwardly open U-shaped cross sectionalprofile with a sealing bed 17 for placing or foaming a lid seal 18therein, wherein, in the closed state of the cover 4, the lid seal 18 ispressed as a result of the clamping force of the clamping ring 5 againstthe upper drum rim 6.

In the first embodiment illustrated in FIG. 2 of a clamping ring closureof the drum lid 4, an annular bead 20 is integrally formed on theconnecting leg 19 of the upper and the lower legs 7, 9 of the clampingring 5, wherein the annular bead 20 is directed radially inwardly and,when the clamping ring 5 is closed, the annular bead 20 engages in anengagement groove 21 formed in the outer rim 15 of the lid 4 forsecuring the lid on the upper drum rim 6.

When the lidded drum 1 is dropped from a height onto the lid rim 8, theclamping ring 5 is upset and the annular bead 20 of the clamping ring ispressed into the engagement groove 21 in the outer rim 15 of the lid rim8. In this manner, the drum lid 4 is better secured on the drum rim 6and the strength of the drum with respect to drops is increased, suchthat the material thickness of the clamping ring can be reduced.

The second embodiment of the clamping ring closure of the drum lid 4according to FIG. 3 is characterized in that, when the clamping ring 5is closed, the annular bead 20 engages on the upper drum rim 6 against asupport ring 22 integrally formed on the outer rim 15 of the lid forsecuring the drum lid 4 on the upper drum rim 6.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

1. A lidded drum of synthetic material comprising a clamping ring of metal for fastening a drum lid on an upper drum rim, wherein, in a closed state, a clamping ring having a U-shaped cross section engages with an upper lid thereof over a lid rim, and engages with a lower leg under an annular contact surface of a border of the drum wall which extends perpendicularly or obliquely relative to a longitudinal axis of the drum, wherein the annular contact surface is arranged under the upper drum rim and forms an upper limitation of an indentation in an upper portion of the drum wall, and wherein the lid rim formed by an inner rim, an outer rim, and a connecting ring, has a downwardly open U-shaped cross sectional profile with a sealing bed for placing or foaming a lid seal therein, wherein, in the closed state of the drum lid, the rim seal is in the closed state of the drum lid pressed against the upper drum rim by the clamping force of the clamping ring, further comprising an annular bead formed on the connecting ring between the upper and lower legs of the clamping ring, wherein the bead is directed radially inwardly and, when the clamping ring is closed, the annular bead engages positively on the outer rim of the lid for securing the lid on the upper drum rim.
 2. The lidded drum according to claim 1, wherein the outer rim of the lid has an engagement groove for the annular bead of the clamping ring.
 3. The lidded drum according to claim 1, comprising a lower support ring for the annular bead of the clamping ring which acts on the support ring, wherein the support ring is integrally formed on the outer rim of the lid rim. 